VERSION: 2004 April 28

TO:  Contact persons of VLBA proposals to be dynamically scheduled

NEWS: 

* A call for proposals for a high sensitivity VLBI array consisting 
  of the VLBA, GBT, phased VLA, and Arecibo was made in the latest 
  NRAO Newsletter, posted at http://www.nrao.edu/news/newsletters/

* The NRAO Proposal Referees' Guide can be found at
  http://www.nrao.edu/administration/directors_office/refguide/

* A complete description of the VLA/VLBA Time Allocation Process 
  can be found at http://www.aoc.nrao.edu/epo/ad/scheduling.shtml

* Information from the VLA/VLBA Scheduling Officers, including a 
  table of approved VLA/VLBA proposals, can be found at
  http://www.aoc.nrao.edu/~schedsoc/

GENERAL: Your proposal has been approved for insertion into a queue of
programs to be selected dynamically for observation on the VLBA.  We
have approved for dynamic scheduling more observations than we expect
to be able to discharge.  To fill an observing slot, we will pick the
most appropriate proposal from the queue based on the referee ratings,
the Scheduling Committee evaluation, and the state of the array,
including the weather conditions.  (The priority of your proposal will
have been E-mailed to you separately.)  Priority bins are high, medium
(second), and low, and reflect the probability of actually being
scheduled.  Monitoring proposals at low priority, even if scheduled,
might not be optimally separated in time; if this will compromise your
science goals, then you should consider reproposing to seek improved
priority.  This memo provides information about how to prepare and
submit your observe files, how to improve your chances of being
scheduled at your current priority, and how to examine activity in the
dynamic queue.

PREPARING OBSERVE FILES: Generic information about preparing a keyin
file for the NRAO program "sched" is available at
http://www.aoc.nrao.edu/vlba/html/vlbahome/observer.html.  The
following points highlight information specific to the dynamic queue.

* You must prepare a sched keyin file in sidereal time rather than
  UT; that is, your keyin file should contain the command LST=VLBA_PT
  The time allocated for your proposal is based in Pie Town LST, with 
  the caveat that the VLBA is scheduled with half-hour granularity, 
  so the actual LST range may differ by up to 30 minutes.

* For some proposals, a range in the number of hours to be scheduled
  is given.  When the observation is scheduled, the minimum duration
  will be allocated, and then will be extended on either end to the 
  extent permitted by neighboring projects or by tape availability.
  Your sched keyin file should cover the entire maximum range.  The 
  LST observation times in your file will not be changed, only the
  date.  Late starts will be handled by activating the file when the 
  array is ready and then skipping forward to the observation 
  scheduled for that time.  You must ensure that any essential 
  calibration observations (e.g., fringe finders) occur within the 
  minimum duration.

* Please submit your preferred dynamic constraints with your sched
  keyin file, by editing the following comment lines as desired and
  inserting them at the top of your keyin file.  The "!" symbol
  indicates to sched that these are comment lines.  Please note:
     + We cannot guarantee that all your preferred constraints, 
       especially those related to weather, will be satisfied 
       when your project is observed.  
     + It is rare to have 9 stations with weather appropriate for 
       1cm or 7mm.  So specifying this combination in your 
       preferences will make scheduling difficult, especially for 
       proposals queued at medium or low priority.

! ================================================================
!   Preferred Dynamic Contraints.  Alter [defaults] as desired.
! ================================================================
! Equipment constraints:
!    Stations.  Below each station code, the "o" indicates an
!       [optional] station that is to be used if it is available.
!       Change "o" to "r" if the station is required or change
!       "o" to "n" if the station is not to be used.
!           SC  HN  NL  FD  LA  PT  KP  OV  BR  MK
!           o   o   o   o   o   o   o   o   o   o
!       Minimum number of stations [9 (6 for 3mm)]:
!       May we swap PT for a single VLA antenna? [yes]
!          Consult http://www.aoc.nrao.edu/~gtaylor/y1gotcha.html
!          to decide.  If you adopt the default, then both PT and
!          VLA1 must be in the stations list in the keyin file.
!    Bands and polarizations.  Below each band code, insert "R" 
!       if the righthand polarization is to be used, "L" if the
!       lefthand polarization is to be used, "d" if dual 
!       polarizations are to be used, or "o" if the band is in
!       your setups but scheduling should not be constrained by
!       its availability.
!           90cm  50cm  20cm  13cm  6cm  4cm  2cm  1cm  7mm  3mm
!
! Weather constraints:
!    [appropriate for bands marked "L", "R", or "d" above
!     and for at least the minimum number of stations]
! Date constraints:
!    Preferred date(s), usually a series start [none]:
!    Excluded dates plus reason [none]:
!    Preferred interval between segments in days [none]:
!    Special conditions (e.g., a series with different
!       spacings in time) [none]:
! ================================================================

* Please ensure that the correlation parameters you submit with your
  sched keyin file are correct.  Once your program has been observed 
  and is being prepared for correlation, we will use the correlation 
  parameters from your sched keyin file.

* For some proposals, a local technical contact person has been 
  assigned.  If you have questions about preparing your sched keyin 
  file, then please seek advice from that technical contact person.

HINTS FOR SUCCESS: You can improve your chances of being scheduled by
accepting the defaults indicated in the form for Preferred Dynamic
Constraints (see above).  You can improve your chances even more by
requesting even milder constraints, such as a minimum of 8 stations
for observations at 6cm.  If your preferences change after you submit
your keyin file, then please E-mail a revised form for Preferred
Dynamic Constraints to schedsoc@nrao.edu.

SUBMITTING OBSERVE FILES: Send your sched keyin file to
vlbiobs@nrao.edu.  The data analysts will verify that your keyin file
can be used by sched to produce the VLBA station control files, and if
a local technical contact person has been assigned, will ask the
contact to verify that the files will likely do what you want done.
Verified keyin files will be inserted into the queue to await
scheduling.

* For programs involving monitoring segments, in which you want to 
  use the same sched keyin file (including its dynamic constraints) 
  for every segment, you may submit a generic keyin file and the 
  analysts will insert segment codes as you instruct.

* Some programs request closely-spaced and multi-epoch segments, with
  different observing frequencies per segment.  We recommend that you
  start with the highest frequency first and assign it segment code
  A, then descend across the epochs with the lowest frequency last.

DYNAMIC QUEUE ACTIVITY: Lists of the titles of all proposals currently
in the queue, proposals from the queue recently observed, and an
approximate priority ordering of the top proposals in the queue can be
accessed at http://www.aoc.nrao.edu/vlba/schedules/this_dir.html.

(end)